CVE-2024-21638
📋 TL;DR
CVE-2024-21638 is an authentication bypass vulnerability in Azure IPAM that allows attackers to impersonate privileged users by manipulating authentication tokens. This enables unauthorized access to IPAM data and potentially Azure resources, affecting all Azure IPAM users before version 3.0.0.
💻 Affected Systems
- Azure IPAM
📦 What is this software?
Azure Ipam by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full administrative access to Azure IPAM data, potentially accessing sensitive IP address management information and using it to pivot to other Azure resources.
Likely Case
Unauthorized access to IPAM instance data including IP address allocations, network configurations, and potentially sensitive metadata about Azure environments.
If Mitigated
With proper network segmentation and access controls, impact is limited to IPAM data exposure without direct Azure resource compromise.
🎯 Exploit Status
Exploitation requires ability to intercept or manipulate authentication tokens, but no public exploit code is available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.0.0
Vendor Advisory: https://github.com/Azure/ipam/security/advisories/GHSA-m8mp-jq4c-g8j6
Restart Required: Yes
Instructions:
1. Backup current IPAM configuration. 2. Update Azure IPAM to version 3.0.0 or later. 3. Restart the IPAM service. 4. Verify authentication token validation is functioning.
🔧 Temporary Workarounds
Network Isolation
allRestrict network access to Azure IPAM instances to trusted sources only.
Configure firewall rules to limit IPAM access to specific IP ranges
Access Control Enhancement
allImplement additional authentication layers before IPAM access.
Configure VPN or bastion host for IPAM access
Implement multi-factor authentication
🧯 If You Can't Patch
- Isolate Azure IPAM instances from internet and restrict internal access to essential personnel only.
- Implement network monitoring for unusual authentication patterns or token manipulation attempts.
🔍 How to Verify
Check if Vulnerable:
Check Azure IPAM version - if below 3.0.0, system is vulnerable.Check Version:
Check IPAM web interface or configuration files for version informationVerify Fix Applied:
Verify Azure IPAM version is 3.0.0 or higher and test authentication with invalid tokens to ensure they are rejected.📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts with malformed tokens
- Successful authentications from unexpected sources
- Multiple authentication attempts with varying tokens
Network Indicators:
- Unusual authentication traffic patterns
- Requests with manipulated authorization headers
- Traffic from unexpected IP addresses to IPAM endpoints
SIEM Query:
source="azure-ipam-logs" AND (event_type="authentication" AND (token_validation="failed" OR user_agent="suspicious"))🔗 References
- https://github.com/Azure/ipam/commit/64ef2d07edf16ffa50f29c7e0e25d32d974b367f
- https://github.com/Azure/ipam/pull/218
- https://github.com/Azure/ipam/security/advisories/GHSA-m8mp-jq4c-g8j6
- https://github.com/Azure/ipam/commit/64ef2d07edf16ffa50f29c7e0e25d32d974b367f
- https://github.com/Azure/ipam/pull/218
- https://github.com/Azure/ipam/security/advisories/GHSA-m8mp-jq4c-g8j6
